Our invention relates to an apparatus having a pair of magnetic transducer head assemblies for data transfer with a double sided flexible magnetic disk. More particularly, our invention pertains to such a data transfer apparatus wherein the pair of head assemblies are arranged for optimum data transfer contact with the flexible magnetic disk.
Japanese Laid Open Patent Application No. 58-77080 filed by the assignee of our instant application (corresponding U.S. patent application Ser. No. 434,400 now U.S. Pat. No. 4,602,306, in the name of Noda) represents a typical conventional data transfer apparatus for use with a double sided flexible magnetic disk. The pair of transducer head assemblies of this known apparatus are both gimbal supported, with their gapped disk engaging surfaces disposed parallel to the normal plane of the magnetic disk. We object to this arrangement of the head assemblies for the following reasons.
The disk engaging surfaces of the head assemblies will stay parallel to the normal plane of the intervening magnetic disk as long as the disk remains absolutely flat, with no force exerted on the gimbal supports via the head assemblies. Being very limply flexible, however, the magnetic disk cannot possibly remain exactly planar during rotation. The unavoidable wobbling movements of the magnetic disk result in the application of higher frictional forces thereon by the disk engaging surfaces, and particularly by their leading end portions, of the head assemblies as the disk slides therebetween. The exertion of the frictional forces is of course undesirable as such forces accelerate the wear and abrasion of the disk.
The gimbaling of both head assemblies, as has been suggested by the noted prior application, gives rise to the additional problem that, upon tilting of both head assemblies during the rotation of the magnetic disk, the leading end portions of their disk engaging surfaces exert still greater frictional forces on the disk.
The wobbling of the magnetic disk also takes place in its radial direction, the disk being clamped only at its central portion and being slidably engaged between the pair of head assemblies at a point spaced radially outwardly therefrom. The undulations of the magnetic disk take place between these points, impairing the proper data transfer contact of the head assemblies with the disk.